The correct answer is: C. 180 m
The minimum turning radius of a taxiway is the minimum radius that an aircraft can turn within while taxiing. This radius is determined by the aircraft’s weight, speed, and turning characteristics. Supersonic transport aircraft are typically very large and heavy, and they require a large turning radius in order to make a safe turn. A turning radius of 180 m is sufficient for most supersonic transport aircraft.
Option A (60 m) is too small for most supersonic transport aircraft. Option B (120 m) is a common turning radius for smaller aircraft, but it is not sufficient for most supersonic transport aircraft. Option D (240 m) is a larger turning radius that is suitable for some supersonic transport aircraft, but it is not the minimum turning radius for all supersonic transport aircraft.